Function cleanupLivestreamThumbnailAfterYouTubeSync

cleanupLivestreamThumbnailAfterYouTubeSync(
    userId: string,
    livestreamId: string,
    thumbnailR2Key: string,
    youtubeThumbnailUrl: string,
    thumbnailUpdatedAt: string,
): Promise<string>
Clears a livestream's R2 thumbnail after it was uploaded to YouTube and stores the YouTube URL. Updates the document first so a failed DB write leaves the R2 object intact for retry.
Parameters
- userId: string
  Owner user id (R2 key prefix validation).
- livestreamId: string
  Livestream row id.
- thumbnailR2Key: string
  Final R2 key that was uploaded to YouTube.
- youtubeThumbnailUrl: string
  Best available thumbnail URL returned by YouTube.
- thumbnailUpdatedAt: string
  ISO timestamp recorded when the thumbnail was uploaded.
Returns Promise<string>
null on success, or an error message when persistence failed.
- Defined in lib/livestreams/cleanup-livestream-thumbnail-after-youtube-sync.ts:14